France's national currency may be disappearing with scarcely a whimper, but it was born in a Gallic flourish of defiance against the English Kings during the Hundred Years War.

In French the word "franc" means "free", and it was the name given to a gold coin minted in 1360 to celebrate the freedom of King John the Good after four years in captivity.

Franc history

1360: King John's franc d'or a cheval

1575: The silver franc of Henri III

1795: The Franc Germinal

France used it to pay, in instalments, a massive three-million-ecu "king's ransom" to his former captors.

It showed King John in full armour galloping on a horse with his sword outstretched - implicitly almost as much of a threat to England as a coin issued earlier by John's father, showing a knight skewering an English dragon with his lance.

But the defiance proved impossible to sustain. France could not keep up the ransom payments and the king was surrendered to the English again four years later. He died soon afterwards.

British forgery

Experts point out that the franc was not so much a new currency, as a version of the pre-existing livre - based on the Latin term - which had been minted to commemorate a particular event.

The sower design: First used for the Franc Germinal

Seen in this light, it was the first French commemorative coin, but one which later became a currency in its own right.

The franc continued to be associated with times of trouble, making its second appearance, as a silver coin, during the 16th Century Wars of Religion and emerging for a third and final time during the French Revolution in 1795.

Latin Monetary Union

1864: Belgium, France, Italy and Switzerland

1868: Greece joins

Others whose coins conform: Albania, Austria-Hungary

While the first two francs had been introduced in the hope of stabilising a monetary system shaken by years of war, the Franc Germinal of the revolution was introduced to end raging inflation caused both by unwise economic policies, and a policy of deliberate forgeries by the British Government.

In this task, it succeeded remarkably well. The one franc coin (minted only in 1803 because a shortage of bullion in the 1790s) retained the same weight in silver until World War I.

'Heavy' franc

The revolutionary franc was also France's first decimal currency, divided into decimes and centimes, replacing the ancient system of livre, sou and denier (12 denier to the sou, 20 sou to the livre) which continued to exist in a different form in the UK until 1971.

De Gaulle: Out with the old, in with the new

The French coins later formed the model for the unsuccessful Latin Monetary Union of 1864, in which all member states - initially Belgium, France, Italy and Switzerland - tired to standardise their coinage to allow free circulation of coins from any one state throughout all the others.

The franc underwent its last big change under General de Gaulle in 1958, who knocked two zeroes off the currency, to undo some of the effects of recent inflation.

On 1 January 1959, exactly 42 years before E-day, the "new" franc, also known as the "heavy" franc was introduced, at a value of 100 old francs.

Some older French people still think in "old" francs, and will therefore have a double leap to make to cope with the euro.